Magnetic anisotropies in ultrathin iron films grown on the surface-reconstructed GaAs substrate

Magnetic anisotropies of epitaxial ultrathin iron films grown on the surface-reconstructed GaAs substrate were studied. Ferromagnetic resonance technique was exploited to determine magnetic parameters of the films in the temperature range of 4-300 K. Extraordinary angular dependence of the FMR spectra was explained by the presence of fourfold and twofold in-plane anisotropies. A strong in-plane uniaxial anisotropy with magnetic hard axis along the [1 1- 0] crystallographic direction is present at the GaAsFe (001) interface while a weak in-plane uniaxial anisotropy for the Fe grown on Au has its easy axis oriented along [1 1- 0]. A linear dependence of the magnetic anisotropies as a function of temperature suggests that the strength of the in-plane uniaxial anisotropy is affected by the magnetoelastic anisotropies and differential thermal expansion of contacting materials. © 2007 American Institute of Physics

The emergence and evolution of Neolithic cattle farming in southeastern Europe:New zooarchaeological and stable isotope data from Džuljunica-Smărdeš, in northeastern Bulgaria (ca. 6200–5500 cal. BCE)

Cattle were of great importance for the Neolithic farmers of southeastern Europe, in particular as farming expanded towards the well-watered regions of Džuljunica (ca. 6200–5500 cal. BCE), one of the earliest known Neolithic settlements in northeastern Bulgaria. The clear stratigraphy and the substantial Bos assemblage from Džuljunica Provided us with a great opportunity to investigate the beginning and evolution of cattle husbandry in the northern Balkans through stable isotope and zooarchaeological analyses. The relative abundance of Bos at Džuljunica leaves no doubt about the importance of beef and cattle herding. Mortality profiles suggest a transition in the early phases of the Neolithic from beef-oriented to mixed beef and milk production husbandry, enabled through intensified post-lactation culling. Stable carbon and oxygen isotope analysis of tooth enamel on a limited number of samples provides no evidence for an extended calving season for increasing milk availability or for vertical mobility. Stable carbon and nitrogen isotope values of bone collagen suggest that cattle were kept near the site, where C3 and C4 plants were available in summer, and that they were occasionally foddered with forest resources in the winter. Cattle experience a diachronic reduction in size on a regional scale, possibly due to farmers' choices aimed at more manageable herds consisting of smaller individuals. Restricting intermixing with local aurochs and the arrival of a new type of cattle may also have contributed to this change. Local factors or inter-regional influences may have influenced the ways cattle husbandry evolved at Džuljunica in particular and in northeastern Bulgaria more generally. More data from the region are necessary to flesh out the role of the interplay among environmental factors, local developments, and inter-regional contacts that facilitate the transfer of skills and traditions relating to the changing modes of cattle husbandry

Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe

Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local European wild boars, although it is also possible that European wild boars were domesticated independently without any genetic contribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process

Kırklarelİ, Türkei: Ausgrabungen in der neolithischen Siedlung Aşaǧı Pınar

The emergence of a new way of living in permanent settlements based on farming, conventionally addressed as the “Neolithic Revolution”, has been one of the most significant turning points in the history of civilization, with time leading to the emergence of more complex socio-economic models. The modalities of this new way of living, after having its initial evolutionary stages in certain parts of the Near East, from the beginning 7th Millennium on began dispersing to other region, thus becoming a global model. In this respect, the quest to find answers to questions when, how and why farming appeared in Europe has always been a matter of controversy. To find answers to these questions excavation at the Neolithic site of Aşağı Pınar, located in Eastern Thrace, the main contact zone of Anatolia with South-eastern Europe. Excavations at Aşağı Pınar have revealed an uninterrupted cultural sequence from c. 6200 to 4900 BC, from the time when the first farmers arrived in Thrace to its full adaptation to local environmental conditions. Aşağı Pınar became not only the key site for the chronology of the Karanovo I to IV sequence in Thrace but has made it possible to discern issues such as settlement organisation, social structuring and subsistence. Since 2010 two ditches could be excavated on a distance of 140 metres. Both ditches have no obvious functions like defense, water supply or working place. Recent observations not only in Aşağı Pınar but also in other Neolithic sites suggest to interpret ditch digging as a cultural phenomenon